System and method for four dimensional angiography and fluoroscopy

Inventors

Mistretta, Charles A. • Strother, Charles M.

Assignees

Mistretta Medical LLC • CMS Medical LLC

Abstract

A method for generating time-resolved 3D medical images of a subject by imparting temporal information from a time-series of 2D medical images into 3D images of the subject. Generally speaking, this is achieved by acquiring image data using a medical imaging system, generating a time-series of 2D images of a ROI from at least a portion of the acquired image data, reconstructing a 3D image substantially without temporal resolution from the acquired image data, and selectively combining the time series of 2D images with the 3D image. Selective combination typically involves registering frames of the time-series of 2D images with the 3D image, projecting pixel values from the 2D image frames “into” the 3D image, and weighting the 3D image with the projected pixel values for each frame of the time-series of 2D images.

Core Innovation

The invention produces a time-resolved three-dimensional image by acquiring image projection data from a subject during a single contrast injection using a single source/single detector system. From at least a portion of the acquired projection data, a time-series of two-dimensional images is generated, and a three-dimensional image substantially without temporal resolution is reconstructed. A time-resolved three-dimensional image is then produced with a signal-to-noise ratio substantially higher than the signal-to-noise ratio of the acquired image projection data by selectively combining the temporally unresolved three-dimensional image and the two-dimensional image time-series.

A subtracted vessel-only time-series of two-dimensional images is generated by subtracting at least one of a time frame and an average of time frames acquired before arrival of contrast from time frames acquired after arrival of contrast during the single contrast injection. The reconstructed three-dimensional image substantially without temporal resolution is registered to the subtracted vessel-only time-series, then the subtracted vessel-only time-series is convolved using a two-dimensional spatial kernel. For each time frame, pixel values are projected along a line perpendicular to the plane of the time-series and the three-dimensional image is multiplied with the projected pixel values to produce the time-resolved three-dimensional image.

Signals corresponding to undesired vascular structures in a region being imaged are zeroed by multiplication using projected pixel values from the subtracted vessel-only time-series of two-dimensional images. The multiplication is repeated at additional angles, and the final image is derived from the minimum values resulting from image estimates obtained by multiplication at two or more angles or, alternatively, by calculating voxel intensity curves as a function of multiple projection angles, identifying anomalies in voxel intensity curves, and averaging voxel intensity for the anomalous voxel over multiple projection angles.

Claims Coverage

The partial content provides three independent claims (clm-00001, clm-00011, clm-00019), each directed to producing a time-resolved three-dimensional image with substantially higher signal-to-noise ratio by selectively combining a three-dimensional image substantially without temporal resolution with a subtracted vessel-only two-dimensional time-series. Across the independents, there are three core inventive feature clusters: acquisition and reconstruction with single source/single detector or bi-plane systems, subtracted vessel-only time-series processing with spatial kernel convolution and perpendicular projection, and multi-angle combination using minimum values or voxel-intensity-curve anomaly averaging while zeroing undesired vascular structures.

Across clm-00001, clm-00011, and clm-00019, the claims cover producing time-resolved 3D images with substantially higher signal-to-noise ratio by selectively combining a temporally unresolved 3D reconstruction with a subtracted vessel-only 2D time-series. The covered processing includes registration, convolution with a two-dimensional spatial kernel, perpendicular projection of pixel values, and multiplication into the 3D volume per time frame; it also includes zeroing undesired vascular structures via the same multiplication. Multi-angle processing is captured either by deriving final values from minimum image estimates across angles or by voxel intensity-curve anomaly detection with averaging over multiple projection angles.

Stated Advantages

Documented Applications

No documented applications found